<template>
	<div class="upload-file">
		<el-upload
			:multiple="multiple"
			:action="uploadFileUrl"
			:before-upload="handleBeforeUpload"
			:file-list="fileList"
			:limit="limit"
			:on-error="handleUploadError"
			:on-exceed="handleExceed"
			:on-success="handleUploadSuccess"
			:show-file-list="false"
			:headers="headers"
			:http-request="httpRequest"
			class="upload-file-uploader"
			ref="fileUpload"
		>
			<!-- 上传按钮 -->
			<slot>
				<el-button type="primary">选取文件</el-button>
			</slot>
		</el-upload>
		<!-- 上传提示 -->
		<div class="el-upload__tip" v-if="showTip">
			请上传
			<template v-if="fileSize">
				大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
			</template>
			<template v-if="fileType">
				格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
			</template>
			的文件
		</div>
		<!-- 文件列表 -->
		<transition-group
			v-if="showFileList"
			class="upload-file-list el-upload-list el-upload-list--text"
			name="el-fade-in-linear"
			tag="ul"
		>
			<li :key="file.uid" class="el-upload-list__item ele-upload-list__item-content" v-for="(file, index) in fileList">
				<el-link :href="file.url" :underline="false" target="_blank">
					<span class="el-icon-document"> {{ getFileName(file.name) }} </span>
				</el-link>
				<div class="ele-upload-list__item-content-action">
					<el-link :underline="false" @click="handleDelete(index)" type="danger">删除</el-link>
				</div>
			</li>
		</transition-group>
	</div>
</template>

<script setup name="FileUpload">
import { getToken } from "@/utils/auth";

const props = defineProps({
	modelValue: [String, Object, Array],
	// 数量限制
	limit: {
		type: Number,
		default: 5
	},
	// 大小限制(MB)
	fileSize: {
		type: Number,
		default: 5
	},
	// 文件类型, 例如['png', 'jpg', 'jpeg']
	fileType: {
		type: Array,
		default: () => ["doc", "xls", "ppt", "txt", "pdf"]
	},
	// 是否显示提示
	isShowTip: {
		type: Boolean,
		default: true
	},
	// 是否显示文件列表
	showFileList: {
		type: Boolean,
		default: false
	},
	// 是否可以多选
	multiple: {
		type: Boolean,
		default: true
	},
	// 上传文件地址
	action: {
		type: String,
		default: "/file/upload"
	},
	httpRequest: {
		type: Function,
		default: undefined
	}
});

const { proxy } = getCurrentInstance();
const emit = defineEmits(["update:modelValue", "onSuccess"]);
const number = ref(0);
const uploadList = ref([]);
const uploadFileUrl = ref(import.meta.env.VITE_APP_BASE_API + props.action); // 上传文件服务器地址
const headers = ref({ Authorization: "Bearer " + getToken() });
const fileList = ref([]);
const showTip = computed(() => props.isShowTip && (props.fileType || props.fileSize));

watch(
	() => props.modelValue,
	val => {
		if (val) {
			let temp = 1;
			// 首先将值转为数组
			const list = Array.isArray(val) ? val : props.modelValue.split(",");
			// 然后将数组转为对象数组
			fileList.value = list.map(item => {
				if (typeof item === "string") {
					item = { name: item, url: item };
				}
				item.uid = item.uid || new Date().getTime() + temp++;
				return item;
			});
		} else {
			fileList.value = [];
			return [];
		}
	},
	{ deep: true, immediate: true }
);

// 上传前校检格式和大小
function handleBeforeUpload(file) {
	// 校检文件类型
	if (props.fileType.length) {
		const fileName = file.name.split(".");
		const fileExt = fileName[fileName.length - 1];
		const isTypeOk = props.fileType.indexOf(fileExt) >= 0;
		if (!isTypeOk) {
			proxy.$modal.msgError(`文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`);
			return false;
		}
	}
	// 校检文件大小
	if (props.fileSize) {
		const isLt = file.size / 1024 / 1024 < props.fileSize;
		if (!isLt) {
			proxy.$modal.msgError(`上传文件大小不能超过 ${props.fileSize} MB!`);
			return false;
		}
	}
	proxy.$modal.loading("正在上传文件，请稍候...");
	number.value++;
	return true;
}

// 文件个数超出
function handleExceed() {
	proxy.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
}

// 上传失败
function handleUploadError() {
	proxy.$modal.msgError("上传文件失败");
}

// 上传成功回调
function handleUploadSuccess(res, file) {
	if (res === undefined) {
		proxy.$modal.closeLoading();
		return;
	}
	if (res.code === 200) {
		uploadList.value.push({ name: res.data.url, url: res.data.url });
		emit("onSuccess", res.data);
		uploadedSuccessfully();
	} else {
		number.value--;
		proxy.$modal.closeLoading();
		proxy.$modal.msgError(res.msg);
		proxy.$refs.fileUpload.handleRemove(file);
		uploadedSuccessfully();
	}
}

// 删除文件
function handleDelete(index) {
	fileList.value.splice(index, 1);
	emit("update:modelValue", listToString(fileList.value));
}

// 上传结束处理
function uploadedSuccessfully() {
	if (number.value > 0 && uploadList.value.length === number.value) {
		fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
		uploadList.value = [];
		number.value = 0;
		emit("update:modelValue", listToString(fileList.value));
		proxy.$modal.closeLoading();
	}
}

// 获取文件名称
function getFileName(name) {
	if (name.lastIndexOf("/") > -1) {
		return name.slice(name.lastIndexOf("/") + 1);
	} else {
		return "";
	}
}

// 对象转成指定字符串分隔
function listToString(list, separator) {
	let strs = "";
	separator = separator || ",";
	for (let i in list) {
		if (list[i].url) {
			strs += list[i].url + separator;
		}
	}
	return strs != "" ? strs.substr(0, strs.length - 1) : "";
}
</script>

<style scoped lang="scss">
.upload-file-uploader {
	margin-bottom: 5px;
}
.upload-file-list .el-upload-list__item {
	border: 1px solid #e4e7ed;
	line-height: 2;
	margin-bottom: 10px;
	position: relative;
}
.upload-file-list .ele-upload-list__item-content {
	display: flex;
	justify-content: space-between;
	align-items: center;
	color: inherit;
}
.ele-upload-list__item-content-action .el-link {
	margin-right: 10px;
}
</style>
